Unit 2: Research Methods

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Transcript of Unit 2: Research Methods

When an outlier(s) skews the mean - making it no longer "typical" of the scoresDescriptive ResearchSome

descriptive research methods (ex. surveys) can be generalizedCANNOT prove cause and effectNaturalistic ObservationSingle cases (ex. case studies) may be misleadingForm of descriptive research - study of animal or human behavior in natural settings rather than the laboratoryWhen observer knows the goals of the study and allows this knowledge to influence their observationsForm of descriptive research - study of a single individual (or a few) to describe their situation by gathering as much information as possible(ex. psychological tests, interviews, observation, medical records)Steps to Correlational ResearchCreate Operational DefinitionsScatter Plotsrelationshipno-relationshipstatistical measure of relationship between two variables (ranges from -1.0 to +1.0)WHY IS CORRELATION IS NOT CAUSATION?Independent and Dependent VariablesVariable manipulated/changed by experimenterDesign Experimental and Control GroupsExperimental GroupIn a controlled experiment, the group subjected to a change in the independent variable In a controlled experiment, this is the group NOT subjected to a change in the independent variableControl GroupPlacebo Effectexperimental results caused by expectations aloneex. no sugar givenRandom AssignmentRandomly assign participants to either your control or experimental groups.Single and Double Blind ProcedureSingle Blind ProcedureOnly the participant is unaware of the group they are inBoth

the participant and the researcher are unaware of the group they are inDescriptive StatisticsForm of statistics used to describe or summarize the results Central TendencyModeMeanMedianMost frequently occurring scoreAverage of the scoresMiddle score in a distributionRangeStandard Deviationdifference between lowest and highest scores 15 - 3 = 12measure of how much scores vary/differ from the mean Inferential Statistics Used AFTER an experiment to form conclusions about the EFFECT of the independent variable on changes in the dependent variableAPA Ethical GuidelinesEthical Principles Governing Research with Human and Animal SubjectsGoals:Describe descriptive research studies with regard to purpose, strengths and weaknesses by taking into account different types (case studies, naturalistic observation and surveys) random sampling, wording-effect, replication, generalization and applicable biases (ex. Social Desirability Effect).Essential Task 2-1:Essential Task 2-2:Essential Task 2-3:Essential Task 2-4:Essential Task 2-5:Essential Task 2-6:Describe correlational research study with regard to purpose, strengths, and weaknesses by taking into account operational definitions, random sampling, correlational coefficient, and scatter-plots.Apply basic statistical concepts to explain experimental research findings using: Inferential Statistics: Statistical significance (t-test and p-value) Describe experimental research design with regard to purpose, strengths, and weaknesses by taking into account operational definitions, independent/dependent variables, confounding variables, control/experimental groups, random assignment of participants, single/double blind procedures, and applicable biases.Apply basic statistical concepts to explain research findings using descriptive statistics: central tendency (mean, median, mode, skewed distributions), variance (range, standard deviation, and normal distributions).Identify the APA ethical guidelines, such as debriefing and informed consent, and identify how they inform and constrain research practices.Unit 2: Research MethodsDescriptive ResearchCorrelational ResearchExperimental ResearchTypes of Descriptive ResearchNaturalistic ObservationCase StudySurveyStrengthsWeaknessesMethodsUse StatsCorrelation CoefficientCORRELATION IS NOT CAUSATIONMethodsSet up VariablesRandomly Assign ParticipantsUse Single/Double Blind ProcedureApply Inferential StatisticsDescriptive StatisticsCentral TendencyVariationTypes of Research MethodsWhat:Research Methods Foundational TermsWhat:Case StudyStrengthsWeaknessesWhat:In-depth/nonreplicable situations SurveyStrengthsWeaknessesWhat:CAN be generalized IF randomly sampledResearch Method Foundational Termrandom sampling/selectionForm of research with the purpose of describing what is going onExample:"What are the eating habits of ARHS students?"StrengthsWeaknessesSome descriptive research methods can be done quicklyGeneralizedWhat:ReplicationDemo 16: Naturalistic Observation and Observer BiasConclusion:DVolunteers conducted a naturalistic observation of the students in the classroom - though there was an observer bias influencing the observationWhat:Observer BiasWhat:Process of repeating a study (with SAME methods) but different subjects/experimenters - used to RETEST resultsMUST be able to REPLICATE in order to GENERALIZE

findingsProcess of applying findings to new situations or subjectsex. findings of a randomly sampled survey can be GENERALIZED to describe the opinion of the whole schoolStudying Clive Wearing is an example of a case studyObserver biasCan not replicateCan not generalize Form of descriptive research - use of carefully worded questionnaires/interviews administered to a (large) group of peopleRelatively fast/cheapWhat:Step

used during surveys - each member of a population is given the same odds of being selected to respond ex. alphabetical list - randomly with number generatorMS for Survey S for Sampling/Selection (this can get confusing with another term we cover - useful mnemonic)population (all of ARHS)Sample (determined with random number generator)When wording changes the results of survey (although same question is being asked)Demo 17: Surveys and Wording and Social Desirability EffectsConclusion:DWording influenced students responses - although the same question was being askedWhat:Social Desirability EffectWording Effectex. Do you support ALLOWING or BANNING tobacco ads?What:When asked directly about a sensitive subject - we may ALTER our answer to what we think is SOCIALLY ACCEPTABLEConclusion:When asked to share responses in public - students were willing to ALTER their responsesTime consumingEasy to

replicateMJust like GENERALIZATION from last unitBehavior is more natural than if they were in the labCan not replicateCan not generalize Observer biasWITHOUT randomly samplingSampling BiasWording EffectSocial Desirability Effect(unrepresentative results)Correlational ResearchAllows you to make PREDICTIONS for future researchWhat:Form of research with the purpose of showing the relationship between two variables and making predictionsStrengthsWeaknessesCORRELATION IS NOT CAUSATION!!!!!!!!!!!!!!!!!!!!!!!!Correlation does NOT

prove cause/effectCuriosity about the worldNow we have an idea what is going on - without manipulating anythingHypothesis creation2 variables"Do the variables vary together?"Select two variables1(ex. height, weight, happiness, salary, IQ, etc.)2"Does happiness vary with salary?"What:EXACT description of how to derive at the VALUE you are measuring(characteristics and HOW to measure the characteristics)Example:Height:Inches, without shoes)Salary:Average weekly earning without bonuses/benefitsHappiness:3Collect randomly sampled/selected

data(Why do we randomly sample?)so we can GENERALIZEWhat:4Graph with points comprised by values of two variables - amount of scatter shows strength of relationshipWhat:r =

+ 0.05VERY WeakThe CLOSER to -1 OR +1 the stronger the correlation-.99 is a stronger correlation than +.98The AP Exam LOVES to ask this.Positive CorrelationNegative Correlation+.97+.14Variable 1Variable 2Variable 1Variable 2(Self-Esteem)(Depression)(Stamp Price)(Year)-.92Low self-esteem and depression are strongly correlated but...Does ice cream CAUSE shark attacks?NOIce cream sales and shark attacks on swimmers are correlatedThird Variable:TEMPERATURE (beach)Was there a strong relationship?Time to make a prediction and consider conducting an experimentAfter ExperimentExperimental ResearchThe ONE and ONLY way to PROVE that one variable CAUSES a change in anotherWhat:Form of research with the purpose of establishing cause and effect between two variablesStrengthsWeaknesses"Does X cause a change in Y?"Confounding VariablesExperimenter biasExperimental Research Foundation TermsAmerican Psychological AssociationConfounding VariableWhat:Hypothesis:Independent VariableWhat:If a child consumes sugar then there will be an increase in hyperactivity.Variable the experimenter measures to see if the independent variable resulted in a CHANGEDependent VariableDemo 18: Experimenter BiasConclusion:DMy preconceived conclusions about the study resulted in an experimenter bias and the creation of confounding variables (ex. type of chair)What:MTip:A hypothesis in this class will be presented as an "If...

then" statementIf a child consumes sugar

then there will be an increase in hyperactivity.FOLLOWS "IF" - IndependentFOLLOWS "THEN" - Dependent1Select operationally defined independent and dependent variables (need to operationally define so the experiment can be replicated)What:ex. participants GIVEN sugarIf a child consumes sugar then there will be an increase in hyperactivity.What:ex. participants GIVEN a PLACEBO sugar23What:Experimental GroupControl Groupex. alphabetical list - random group generatorWhy:4What:Double Blind ProcedureWhat:Why?Variables that a researcher FAILS to control for OR eliminateExperimenter BiasErrors in a research study due to the prior beliefs of the experimenterWhat:ex. my clear bias in the previous demoHelps REDUCE

confounding variables and experimenter biasWhat if the researcher put all of the gender in the control group? Adds a CONFOUNDING VARIABLE.Random Assignment reduces thatMOnce you have participants - the next step is to put them into groups...or in the other words - put their into groupsrandom assignmentCONS lie and these make your results a CONCONfounding VariableMReduces BOTH experimenter bias AND placebo effect - essential when testing new drug treatment5What:RepresentativePopulation(Random) SampleCan we make conclusions?Inferential Statisticst-test and p-valueWhat:A calculation conducted after an experiment to determine IF the results were CAUSED by manipulating the independent variable OR by dumb luckyou will NEVER be asked to calculate thisBUTThey LOVE

asking what the p-value meansa t-test provides the p-value.100.50DUMB LUCK.051.05Statistical SignificanceWhat:The difference found in the experiment was REAL and NOT by chanceIF a p-value is 5% AND BELOW (.05) - the results were STATISTICALLY SIGNIFICANTIn a study of power and self-image, participants were not told the true purpose of the study; instead, they believed they were participating in a business simulation. Researchers randomly assigned participants to a high- power (n = 44) or low-power (n = 44) condition. In the high-power condition, participants recalled a time when they had power over others, and in the low-power condition, they recalled a time when others had power over them. Participants were asked to adjust the height (in centimeters) of an electronic graphical image (an avatar) of themselves to reflect their personal appearance. Results indicated a statistically significant difference in participants’ perceptions of their own height across the two conditions.

- Create a bar graph illustrating the results of the study. Correctly label each axis.

- Explain why the researchers can conclude that there is a cause-and-effect relationship between the independent and dependent variables.

- Explain what statistical significance means in the context of the study.

- Explain why debriefing would be necessary in the study. ScoredThis would NOT be enough - when on to SPECIFY what that meansScored"Participants in the high-power condition created taller self-images."Unlike 2015 - this year actually HAD a difference in results (6 vs. 4)- so the graphs needed to differScored:Did NOT Score:As we know - only way to prove cause-and-effectScored:Statistical significance is shown by the p-value If BELOW 5% (.05) - the experiment WAS statistically significant and NOT due to chanceScored:Always connecting back to the the prompt2007 AP ExamFound statistically significant results?Looks like you have yourself a theoryOther Stats: DescriptiveWhat:Placebo10 mg100 mgActivity TreatmentPre-TreatmentPost-TreatmentWhat:Way of checking what is average/typical3 FormsSkewed DistributionWhat:ex. adding Tom Brady to the mean income of those in this classroom would result in a positive skewlEftnEgative skewrIghtposItive skewMWhen distribution is skewed:MEDIAN is used to describe central tendencyPositive SkewWhat:151212853rangeWhat:Small Standard Deviation = Scores tend to be similar to one anotherF Block has the smallest SD - meaning the scores in F Block tended to be CLOSER than in D/E Block(often displayed on a BAR GRAPH)Normal Distribution (Bell) CurveWhat:Distribution curve where the mean, median and mode are all the sameex. intelligence tests are designed for results to be normally distributedNormal distribution curves always look like this:You will need to memorize ".02, 2, 13 , 34"For baseball fans:

Which of the following scores is within one standard deviation of the mean?

(A) 132 (B) 77 (C) 96 (D) 62 (E) 140Answer:96What percentage of scores fall between 115 and 85?What percentage of scores fall two standard deviations above and two standard deviation below the mean?701300-2213 + 34 +34 + 13 = 95 AnswerThe answer on the AP Exam will be 95 - we remove the decimals for easeFor example - adding 10 points to EVERY score wouldn't change this (though it would change ALL central tendencies )APA Ethical GuidelinesWhat:Still acting "hyper"What:Highlights:informed consentWhat:confidentiality - unless agreed upon in advancedebriefingWhat:Independent is what you put "IN" the cupWhat:Founded in 1892 - largest scientific/professional organization of psychologistsOriginal President:The "Original G" - G. Stanley HallMSecond President (first female):Academic research must be approved by APA ethics board (based on APA Ethical Guidelines)Margaret Floy Washburn(F-W for First Woman)To Note: Percentiles.02%.02%If you ever see the term "percentile" regarding this curve - they are just referencing the %'s in each deviation50th percentile84th percentile100th percentile(100%)(50%)(5.1%)(5%)the process of describing the research AND obtaining the subjects' consent based on an understanding of the project's methods and goals - IF possible

(deception is allowed)Process of giving participants in a research study a complete explanation of the study after the study is completedDo NowWhich APA ethical guideline do you believe is the most important and why?